This invention relates to a fire-retarding window assembly comprising a frame and at least two window panels.
Fire retarding window panels are conventionally mounted in a frame against an adjacent wall in such a manner that, in the event of fire breaking out, the flames are prevented from travelling through the space occupied by the panel for a desired time period, which period depends upon the construction of the panel, and may for example be 15, 30 or 60 minutes. Of course, the nature of the frame into which the window panel is fitted, and the manner in which the window panel is fitted into the frame, both have an important effect upon the fire resistance.
Architects increasingly want to be able to construct large window assemblies comprising a frame and at least two window panels. They desire these assemblies to have a minimum of visible assembly components, that is to maximise the transparent area. This can be done, for example, by arranging the window panels in side edge-to-side edge relationship and securing the panels only at the top and the bottom. However, it has not previously been thought possible for window assemblies constructed in this way to successfully act as a seal or barrier to flames and smoke. In the event of fire, such an assembly would become exposed to heat in a non-uniform way, as a result in particular of the large size of the assembly, and would be expected to become variously or irregularly deformed, so that the flames would be able to penetrate between the panels.